A statement from the All India Institute of Medical Sciences said, "Kamla Advani, wife of LK Advani, was brought to the main casualty, AIIMS at 5:10 pm in a very serious unconscious and unresponsive condition. Immediate evaluation revealed the patient to be in cardiopulmonary arrest."

It further said that immediate resuscitation measures were provided by a team of doctors.

"However, despite 60 mins of intensive efforts, she could not be revived and was declared dead at 6:10 pm," the statement said.

Aiims director MC Mishra said, "She was pulseless, her blood pressure was not recordable and she was unresponsive. Resuscitative measures were put in place and after about an hour she was declared dead."

Kamla Advani (83) leaves behind, besides her husband, a son and a daughter.

She had been suffering from age-related problems for some time and was on wheelchair for the last few months.

Prime Minister Narendra Modi on Wednesday expressed deep pain and sadness over the demise of Kamla Advani, saying she had always inspired and motivated party workers.

I recall my many interactions with Kamla Advani ji. My thoughts are with the Advani family in this hour of grief. May her soul rest in peace — Narendra Modi (@narendramodi) April 6, 2016

President Pranab Mukherjee also expressed his condolences. I fondly recall many visits of Smt. Kamla Advani to Rashtrapati Bhavan accompanying Advanji and her endearing presence #PresidentMukherjee — President of India (@RashtrapatiBhvn) April 6, 2016 Mukherjee also said that the veteran leader's wife was a soft and cultured woman who left a lasting impression on whomsoever she met.

"I condole death of Kamla Advaniji. May God give strength to the bereaved family," Yadav said in his condolence message.

Extending her condolences to the veteran leader and other family members, Congress President Sonia Gandhi said she shares the pain caused by their loss and prayed for the departed soul.

Uttar Pradesh Governor Ram Naik and Chief Minister Akhilesh Yadav also expressed profound grief. In his message, the governor said that whenever Advani was busy in elections, she would handle household responsibilities and also actively participate in poll campaign.

The Advanis were married 51 years ago, in February 1965. She was a social worker and had worked at the General Post Office.

RSS joint general secretary Dattatreya Hosabale tweeted, "Saddened by the demise of Kamla Advani. She lived an ideal life by Advaniji's side & an affectionate Mata to all of us thru her hospitality."

Expressing his condolences, Congress vice-president Rahul Gandhi tweeted, "My sincere condolences to Advaniji on the passing away of his wife Kamla Advani. My prayers are with him & his family in this time of grief."